ModelItem color with IOS won't work

Hello,

is anyone else experiencing similar issue:

I have application parameter called Stop which controls the color of ModelItem. I input the new value of app parameter Stop using JS:

app.params.Stop = 'rgba(255,0,0,0.5);';

This works well in the preview and with Android Thingworx View but not with IOS devices. Am I doing something wrong or is this a bug/not supported functionality with IOS Thingworx View

Best regards,

Juho-Matti